DirectX11 Bad Knouhow: VertexBuffer / IndexBuffer Write

DX11_Vbuffer_Ibuffer.cpp

	ID3D11Buffer*           m_pVertexBuffer;
	ID3D11Buffer*           m_pIndexBuffer;

    //
    D3D11_MAPPED_SUBRESOURCE msr = {};
	HRESULT hr;

	// vertices upload
	hr = m_context->Map(m_pVertexBuffer, 0, D3D11_MAP_WRITE_DISCARD, 0, &msr);

	if (FAILED(hr))
		return;

	memcpy_s(msr.pData, sizeof(vtx_buf), vtx_buf, msr.RowPitch); // 頂点コピー msr.RowPitchで全体を書き換えないとまれに落ちる
	m_context->Unmap(m_pVertexBuffer, 0);

	// indices upload
	D3D11_MAPPED_SUBRESOURCE ires = {};
	hr = m_context->Map(m_pIndexBuffer 0, D3D11_MAP_WRITE_DISCARD, 0, &ires);
	if (FAILED(hr))
		return;

	void* idxbuf = ires.pData;
	if (idxbuf) {
//		memcpy(idxbuf, idc_buf, sizeof(uint32_t) * m_idc_cnt);			// 書き換えたインデックス数のコピーだとまれに落ちる
		memcpy_s(idxbuf, sizeof(idc_buf), idc_buf, ires.RowPitch);      // msr.RowPitchで全体を書き換えないと落ちる
		m_context->Unmap(m_pIndexBuffer, 0);
	}